Because of the high prevalence of C9orf72 mutations in cases of ALS, and because mutations in C9orf72 have also been associated with other neurodegenerative disorders, such as Parkinson’s disease and frontotemporal dementia (FTD), C9orf72 is a promising candidate for targeted antisense therapy [191,195,201,202,203]. This evidence concerns the gene C9orf72 and Parkinson disease.